8n no spark

[Brian70ss]

Hi guy's been a while. I have an issue I could use some help with. I haven't messed with this tractor for about 5 yrs. Decided it was time to get it running. It's a 48 front mount 6 volt. Installed new battery and gas and then no spark. Removed the distributor and points was oily so I replaced the points, condenser and plugs (437's). Still no spark. I ran a wire directly from the negative post to the distributor and it fired up and ran. I have 6.2 volts at the distributor connection as long as I leave it unhooked. If I hook it up I have 0 voltage. I'm guessing I have something wrong in the distributor. I'm not really sure where the nylon screw went so it may be shorting through it. Please give me some advice. Thanks brian

 

[Bruce(VA)]

" to the distributor "

That covers a lot of ground......and is pretty hard to do.

Where exactly are you connecting the jumper wire to the distributor? Are you connecting it to the post on the top of the coil?

If the tractor runs w/ the wire connected......and stops when you remove it......why do you think the problem is in the distributor?

" I'm not really sure where the nylon screw went "

Again....please help me with that.....what nylon screw?

Sorry if I'm dense. I've got four 8N's, 3 of them are front mounts & I can't figure out what you are saying.
75 Tips

 

[souNdguy]

remember. when the points are closed they complete a circuit to ground.
if you have 6.2v at the top of the coil and it goes to 0 when attached, then something upstream is bad. like bad switch or wire connections.. as evidenced by it running when hotwired.

 

[Brian70ss]

yes attached to the post on top of the coil. I am assuming it is the distributor because I seem to have 6.2 volts at every connection i check. I'm thinking switch is ok because i have 6.2 volts on both sides when on and it drops out when off. Resistor has same 6.2 volts on both sides as if it's not working properly.

 

[HCooke]

No, you have something wrong between the battery
and the top of the coil (otherwise it would not
run when hot wired)!

 

[Royse]

With the wire disconnected you have an open circuit.
In an open circuit no current flows and with no current flow there
is no voltage drop. Thus you read battery voltage everywhere.
That is normal.
If it runs when hot wired the distributor is good.
Try just jumpering around the key switch.
It is possible for the switch to connect voltage like it is and still
be unable to handle the current when the wire is connected.

 

[souNdguy]

It's ohms law. you are unfamiliar with it.

when ther eis not a completed circuit. bat voltage can be read at points before ground.

 

[Hobo,NC]

(quoted from post at 03:55:28 09/26/14) yes attached to the post on top of the coil. I am assuming it is the distributor because I seem to have 6.2 volts at every connection i check. I'm thinking switch is ok because i have 6.2 volts on both sides when on and it drops out when off. Resistor has same 6.2 volts on both sides as if it's not working properly.

If you straight wired it and it ran Your have a bad connection there are not many it should not be hard to locate...

My favorite way to eliminate it is to use a old headlight.. Remove the wire from the top of the coil hook it to one terminal of the headlight and ground the other... Most headlights will pull 4 amps and load the circuit enuff to verify all the connections are good/bad... Forget the voltmeter for now unless you want to do a voltage drop test to locate the issue...

 

[greywolf224]

Take that same jumper wire and leave it connected to the coil.

Take the other end and touch the starter solenoid where the battery cable connects to. try starting the the tractor does it run? If so...

touch the jumper wire to the bottom center nut of the oem resistor pad. Where all the wires come togather. Try starting. Does it run? If so

Touch the wire to the upper left side nut of the OEM resistor. Try starting. Does it run? If so....

Go to the left nut on the OEM resistor. Does it run? If so....

What else do you have between the OEM resistor and coil? Should think nothing. Only wire.

 

[Brian70ss]

thanks for the help guys. Finally got back to working on it. It was a bad connection on ammeter. It had melted the plastic around it from being loose. Replace gage and wire. Now up and running.